It is my belief that hard drives could be the future of domestic audio.
They've been in the wings long enough for early adopters to have little interest
in HDCD, SACD & DVD-A, knowing the future lies elsewhere. It is time the
music industry woke up & smelled the coffee. When my sons (aged 10 &12)
talk about & listen to music with their friends they don't think about cd or
even radio first, they go online & download sample tracks. Those dinosaurs
among us who still subscribe to portable hard-software (lp & cd) are not in
the buying public the music industry wants to reach. Face it, if an artist as
revered & successful as Mavis Staples (of the legendary Staples
Singers) had to fund her own 2005 lp, because not one record company
was interested, because those record companies only want fast-buck-Beyonces
among their female artistes, they'd better wake up to new methods of delivery.
The cd buying public doesn't want the cds they want to sell, my children's
friends only download, they never buy recorded music as cd, lp or
tape. In a very few years cd buyers will be in less of a minority than lp buyers
are now. The music biz needs to pay attention to this new market rather than the
R.I.A.A. trying to sue 400 students across 18 US college campuses for
filesharing; most will pay a little for quick downloads but some of us will pay
extra for premium quality downloads.

Hard drives look like the next viable hifi storage medium. DVD-R have not
replaced VHS recorders for time shifting TV programmes, those who have replaced
their VCRs for this purpose now buy hard drives, DVD-R are bought by those
wishing to duplicate DVDs.

"What has this to do with high quality
stereo?" demand plebs, stage left"Absolutely everything",
replieth the scribe, "user fine-tuning is back, big stylee!"

One of the shortcomings of cd for the inveterate tweaker is the limit to the
diversity and degree to which users may fine-tune the output compared to lp.
Vinyl playback allows cartridge electrical-loading changes, tracking force, bias
variation, arm-damping, cartridge alignment, not to mention different cartridge
bolts, suspension tuning and the dreaded VTA. Upsampling & oversampling are
about all that's available from most cd. The changes we hear from them may be as
much due to the algorithms involved as to the sampling rates themselves and
provide limited scope for the tweaker.

Hard drives loaded with raw data at audiophile sampling rates could be as
much a boon to hifi enthusiasts as buying 2nd generation mastertape dupes used
to be. Audio casualties like the TNT community would be willing to pay extra for
higher sampling rates and longer word-lengths for direct downloads of our
favourite music, while the majority prefer the speed and low cost of compressed
formats like MP3.

This can only happen once we are all equipped with audiophile quality memory.
Indeed, as schoolboys loitering in 70s hifi shops, the first time we discussed
sampling audio into a digital datastream it was without any idea of committing
this datastream to anything as primitive as tape or silver disc, but storage in
computer memory, as was already being described in the electronic journals of
the day. Today we live in that future predicted in the 70s even if we're not
wearing lurex suits, substituting pills for meals, or travelling by teleport, as
was also predicted.

The fledgling audio hard drive market already seems to be split between two
target consumer groups. Some are marketed at lifestyle multiroom solutions,
where a central hard drive may serve to several rooms in one house. Linn's Kivor
hard-drive is sold with key audio features like "Knekt Kivor is a
pitch-accurate hard-drive based concurrent archive and retrieval system".
But it is also merely one element of a lifestyle range whose marketing thrust is
not directed at the Real Stereo community: "The KIVOR TUNBOKS
is the ultimate source product...and can be concurrently accessed by up to 16
users."; "simultaneous access...interface with Linn KNEKT system...third
party control via RS 232 and Ethernet" boast the lifestyle suppliers of new
Linn to yachts & loft spaces. However, the Zero One Ti48 archive
boasts features we might expect from a product aimed at hobby audiophiles.

The Ti48 falls into the other hard-drive market, intended as an archive
enabling easy access to a large music collection without repeated trips to a
storage cupboard filled with little plastic discs each offering less than an
hour of music each in most. The multiroom scene has little of interest to the
Real Stereo enthusiasts who populate this webzine, but the archive
concept will enable us to become couch potatoes of the highest order.

How often have you been gradually mellowing, in your bathrobe, enjoying a
bottle of wine, listening late at night to a particular artist reach the end of
one album...then silence? You realise you will have to lever yourself out of the
chair to seek another disc by the same artist, only to remember it is in the
cd-changer in your car locked outside.

If you are unfamiliar with this scenario you are clearly not sybaritic enough
for this page!

The Zero One Ti48 hard-drive (& cd transport) and AR38 DAC
are impressive, massively constructed silver fronted behemoths reminiscent of
stuff like Accuphase and Musical Fidelity. They arrived from
Singapore as the first samples in Europe encased in superb packaging. Pricing
for markets in North America, Western Europe, Japan, Australia and New Zealand
is in $US, a total of $3960 for the pair (plus shipping & taxes). Zero One
currently intend to sell direct with a 30 day home trial warranty, in addition
to 12months guarantee. Expensive tweaky accessories are already being sold this
way. For other markets such as the rest of Asia, Zero One anticipate
dealerships in major cities. I live near a city of a quarter of a million
inhabitants which has not been able to sustain a real hifi shop for more than 10
years; a shop will open & close again after less than 2 years. The serious
stereo community might now be only large enough to sustain a critical mass by
Internet and mail order.

The Zero One hard drive & DAC arrive in two enormous packages to protect
them from the rigours of international shipping. These cardboard monoliths
contain substantial mass, stick a circle of these boxes in a field and expect to
find Druids worshipping there at sunrise. Everything you need to get started
lies within, including the batteries for the remote control and a set of basic
quality leads, including the I^2S interface.

Users are faced with a 10mm thick milled aluminium front centre-panel flanked
by 5mm thick side-panels, reminiscent of Musical Fidelity X-series on steroids.
The milled finish implies craftsmanship rather than production line, and I hope
this individuality stays throughout production. The sides and back are folded
& powder-coated, not the clangy biscuit tins regular readers know I hate.
The base panel benefits from constrained layer damping too. The instructions
impune users not to obscure any of the cooling holes and the class-A output
stage of the DAC will inevitably run hot whether idling or playing as class-A
demands constant high standing current to maintain its operating point, indeed
they tend to be hottest when passing no signal for hours. This limits
experiments with pucks and case dampers, my trusty brick-on
Isonodes would work where space permits, but is aesthetically questionable
and the Jade
IsoDuo (reviewed in part 6 of the saga) might also help where space is
limited. The knuckle-rap test produced a minor improvement when thus loaded so
this is how I begin the test.

Zero One Ti48 Archival Transport Techie stuff

The Ti48 is
described as an "upsampling archival CD Transport" capable of storing over 350
hours of uncompressed audio in 240Gb hard disk drive (HDD). But it does much
more than just store red book data from your cd collection. The Ti48 is
superficially a PC running on Linux OS Zero One custom software, but
attention to detail makes this comparison as useful as describing my Ducati as a
bike. The sound card is shielded in its own box, mounted on custom isolation and
powered from its own very low-noise, linear, opto-isolated, regulated 5v supply,
shielded from the main switch-mode PSU. The 5v line even has a shielded cable.
This level of attention to isolation would seem to me to be worthwhile as
regular readers can guess.

The sound card is only used to extract the digital audio from either the
DVD-ROM or HDDs. From the sound card, the signal is sent via the Zero One
custom 24/192 I^2S cable to the DAC. I^2S is a Philips proprietary
data transmission protocol, also used by Accuphase whose implementation is
rumoured to use a shared clock. Zero One's separate clock technology should
enable a genuine 24bit 192kHz transmission by interleaving two 24bit 96kHz
channels. It may seem strange for a start-up company to adopt an uncommon
interface standard in its first product, but it gives them absolute design
freedom to optimise every link in the data chain to match their particular needs
rather than bodge to fit existing audio technology. The I^2S output is
supplemented by a S/PDIF coaxial (RCA) and a TOSLink optical inputs &
outputs but these would prevent use of the Ti48 features that make it unique, so
they're superfluous.

The custom software uses Linux as the operating system. Again, this is a
brave decision given the ubiquity of Windows platforms and and Windows Media,
but Zero One decided to write their own software to ensure that there are no
crashes and other non-audio problems, familiar to all of us who use Windows.

The digital filter choices, up/over-sampling and other audio functions are
selectable with simple menus from the easy-to-read bright
blue alphanumeric display legends reproduced here. These options are
computed with 64-bit floating point maths, which is big-style processing
capability more familiar in mainframe than pc environments. I suspect this
processing power could go some way to ameliorate some of the criticisms,
principally of potentially jitter prone, of
non-integer upsampling (48.1kHz, 96kHz, 192kHz),
figures that have no relationship with red-book cd, but with other digital audio
applications dating back to DAT (Digital Audio Tape). The Ti48 also offers 2x
(thus 88.2kHz) and 4x (thus 176kHz) oversampling, which will enable direct comparison
of these rival approaches, with all other variables controlled.

Regular readers are aware of my obsession with construction integrity &
vibration isolation so the low-resonance case, with a constrained layer damped
base, comprising two sheets of different thickness metals sandwiching a
compliant foam, score credibility points with this reviewer. The HDDs and
DVD-ROM drive are all mounted on rubber grommets and the HD mounting bracket is
itself compliantly-damped. Excellent, but the feet are horrible hard plastic and
one of them is even loose.

The Ti48 is optimised for quiet running using ultra-quiet switch-mode PSU for
the PC components, a cooling fan that is much quieter than a pc, and virtually
inaudible from 1 metre. The simple alpha-numeric
screen displays four lines of menu text with all functions available by
the simple familiar DVD style remote-control, which avoids the extra junk (mouse
& screen) of pc based music sources that demand space.

Transport is a Toshiba DVD-ROM drive that is mechanically strengthened by
Zero One. The the buffered input for the DVD-ROM + motherboard was found by Zero
One to perform better for error correction & jitter than audio cd drives and
it permits more computing power using an off-the-shelf chip.

The custom software permits a whole bunch of output options, in addition
sampling rate selection, to tailor the flavour to suit listener taste and match
recordings. Filter rates are selectable, ranging through five options from the
familiar red-book "brick wall" down to no filter at all. The options are
denoted:

None no filter at all with risk of ringing,
parasitic excitement, rf instability of power amplifiers, especially
global-feedback types.

Dither, or noise shaping, is also selectable. This is particularly welcome to
analogue lovers, as much of the individual character of analogue systems may be
attributable to the particular way the signal diminishes into the system noise
floor. Psychoacoustic analysis has demonstrated that our perception of noise is
neither linear nor constant. Our ability to detect wanted information from noise
is context dependent and continuously revised by each passing stimulus. A visual
analogy might be the random noise artefacts in digital imaging and their more
obvious nature caused by the similarity of each defect, compared with dissimilar
dust marks on the surface of a traditional silver-gelatine print. Likewise the
moire patterns caused by fine textures resonating with the sensor chip
construction are more distracting than the random grain-clusters of silver
halides in a negative or transparency. Both these problems are easily fixed in
digital imaging using dithered noise that reintroduces a base-line of chaos that
is less distracting to our gestalt-seeking order-imposing minds. The
opportunity to compare the effects different orders of dithered noise means
playtime for audiophiles.

None no added noise

TPDF triangular PDF dither added

Nshape high-passed dither at the Nyquist limit

Nyquist second-order noise shaping

The Dithered noise options would only have any potential benefit when the
Ti48 is connected to a DAC that is capable of accepting greater than 16bit
wordlength. Whatever the conversion chipset, the receiver chips may truncate to
16bit maximum. The Ar38 can accept data up to 24bit and I assume that the Ti48
Archive will usually be partnered with the Ar38 DAC to enable the benefits of
their I^2S interface. The wordlength options of 16bit; 18bit; 20bit; 24bit are
rendered redundant by the dither options. Unless you use the Ti48 to test DACs
from other manufacturers where 16bit would be necessary, I can imagine no
circumstances when users will select anything but 24bit and then fine-tune with
dither.

A crude analogy of the the dithered noise contribution would be to imagine it
fills in the gaps below the least significant signal bit, thus enabling complete
detection of that data present. This will have the effect of swamping those
artefacts that are analogous to the moire patterns in digital imaging.

Zero One did consider making output preferences programmable for each track,
but decided this might make the whole archive process too clunky for most users.
Given that some audiophiles are anally-retentive enough to note VTA settings on
their lp inner-sleeves, I have suggested to Alvin that this might be a popular
feature on a future model.

I asked whether a vinyl input might be a future idea to enable us to archive
our precious collections and was told that this has already been considered, but
R&D will only begin if customer demand is shown to exist. In order to encode
an LP at 24 bits/96 k which is the minimumZero One believe
is required, HDs of really large capacity eg.500gb will be needed. Such beasts
are not currently quiet enough for audio use. Although Analogue-Digital encoding
could include options for cleaning noise from lp or analogue tape, and such
software is available currently for LP archiving, any filter subtly changes the
encoded music from the original LP. If an lp archive facility were offered
Zero One would prefer to minimise signal processing, which I find
encouraging.

Those with big vinyl collections of material not available on cd or only
available on inferior cd transfers should make suitable offerings to their
deities to bring forth this manna. This information came from a personal
briefing from designer Alvin Heng and is not yet available on the Zero One
website or in their literature so we can only guess when it will be available to
consumers.

Alvin also believes that high quality downloads are a long-way into the
future, although I am more optimistic. This should be the future of domestic
audio as soon as the record companies remove their collective heads from their
collective backsides. Alvin correctly notes that the world will need an
infrastructure of higher-speed broadband connections (perhaps ADSL2), that
actually work (my modem & ISP are set at 1.1Mbps but it behaves like about
350kbps because of the ancient telephony infrastructure), but this will happen
for other reasons anyway. Alvin doesn't "think it will get beyond 16/44.1 for
quite a while, maybe a decade or more. [he] doubts there would be significant
demand for 24/96 quality music downloads." Perhaps the companies that manage
to make a profit from 180gm vinyl reissues will find a profitable new niche
offering this service to sufferers of audiophilia nervosa.

Ar38 DAC Techie Stuff

The Ar38 DAC sports cool blue LEDs and accepts digital inputs from either
co-ax sp/dif or the Zero One I^2S from the Ti48. The I^2S link can receive up to
24 bits/192 kHz from the Ti48. The sp/dif input allows upsampling other digital
sources to 24 bits/96kHz. It also features a low resonance aluminium case with
compliantly-damped base.

The Ar38 is described as fully dual mono, with discrete class A circuits
without any global feedback. The analogue stages are direct coupled meaning no
series capacitors in the signal path, with important benefits in transparency
& group delay, especially at low frequencies. Full marks to the tech-spec,
they've covered every audiophile preference and allowed choices of every
parameter where no hegemony exists.

The output is fixed, Alvin Heng dislikes digital volume controls and believes
the analogue volume control belongs in a good preamp where there is less
electronic noise and more appropriate power supplies, like the integrated
amplifier Zero One are currently developing. My experience with the
Shanling is that the volume control is slightly more transparent than a pre-amp
when used with the valve buffer direct to a power-amp, but that attenuation in
the pre-amp is better than from the direct solid-state feed.

The Ti48 & Ar38 digital processing follows the current hegemony of Burr
Brown & Crystal; and the DAC is a BB PCM1704 multi-bit
Digital-analogue-converter. The high accuracy custom-made TCXO clock should
enable these established chips to perform to their optimum. SP/DIF and I^2S
inputs are handled differently: in I^2S mode the Ti48 feeds digital data direct
to the Burr Brown PCM1704 DAC to minimise jitter. The SP/DIF input is upsampled
by the ubiquitous Crystal CS8420 chip and is fed to the Burr Brown PCM1704 DAC
via the Burr Brown DF1704 receiver. Received wisdom is that these are the
current cream of the processors crop, and they appear in most products with any
pretension to high end cd replay.

In Use

This pair is comparable in size & weight to my Michell Gyro
SE/Hadcock/Naim front end and this is the benchmark by which it is judged,
although the currently weak US dollar makes the Zero One combo rather less
expensive than that vinyl spinner. Think of the Ti48 as the turntable/arm and
the DAC as equivalent to the cartridge/phonostage. The comparisons are even more
relevant when one considers the tweakery available to fine-tuners of vinyl
playback which is equally user involving on the Ti48. It has over 40
user-selectable playback combinations of up&oversampling, digital filters
and dithered noise. Even VTA twiddlers will find enough to get paranoid about
with the Ti48, endlessly worrying whether this song is better with the "Purist
filter" or the "HQ1 filter" or the "HQ3 filter", at 88kHz or 176kHz or...etc,
etc. It also has to compete with direct cd replay from its own drive, also with
these options. Phew!

The Ti48 & Ar38 Could do with some front panel operation for losers of
remotes, a menu button, scrollers & enter would be
enough. Better still would be a modest little touch screen as seen on the Classe
Deltas. The remote control will be familiar to anyone who owns a television or
dvd player. It's a generic plastic thing weighing just 125g (including 35g
batteries) and looks & feels really cheap next to the extruded aluminium
225g Shanling CDT100c remote. Pride & pleasure of ownership would be greatly
enhanced by a more tactile remote control as it is the principal interface
between owner & product.

Maximum gripe is also with this horrible plastic remote control. A single
press of its buttons often scrolls through two functions or flips to a function
and back again in a single stroke. Furthermore, the play-pause-stop
buttons sometimes do no such thing while listening to the hard drive. Trying to
jump one track or rewind part of a song often results in chaos. The functions
are fairly straightforward but the learning process is impeded by action being
unrewarded by the desired result. The double jumps are particularly frustrating
when users notice that the alpha-numeric keypad is of the mobile-phone variety
that requires multiple strokes of one key to reach the desired letter and this
will be an essential tool when users have over 100 cds archived. The
alphanumeric pad was better than the "menu" & "OPTS" buttons
but I have no confidence that it will work correctly anytime I pick it up. No
matter how the Ti48 performs I could not live with it if this remote control
remains part of the package.

If this seems petty, remember that the remote control is the user's only
interaction with the Ti48 once the cd has been uploaded. Placing a cd in the
drawer is the only other activity in the user interface, and even that action
requires the remote to "open" and "close" the drawer. This is a
US$4k purchase of a new source including interconnects and a dysfunctional
remote control does not belong at this elevated price-point. Every visitor,
especially style conscious women, who encountered the Zero One combo commented
on the cheap light remote control and how it doesn't belong with such a
product.

The "quick start" section of the instructions runs to 13 pages! Owners will
be on a steep learning curve from the outset. Plus, there are programme paths
integrated into the system that are not yet available but will become available
later purchased as hardware upgrades or available online. This level of future
proofing will be a boon to those of us resistant to new technology purchases.

Listening

It is actually much easier to use the Ti48 than the foregoing
paragraphs imply, apart from the quirky remote control. I suffered a
brain-injury in a motorcycle accident that makes it difficult for me to learn
new processes & sequences, so if I can do it so can you. From cd directly on
the default settings the sound is good, comparable to cd players in the US$3k
territory. The soundstage not quite as big & sensuous as the Shanling
CDT100c valve buffered output, but it is wider & deeper than my hotrod
Rotel RCD965BX discrete, that has more BlackGates than a prison and
much bigger than the Avondale AAA5. Pace is good, but
rhythm & timing not quite as good as the Naim beating Avondale AAA5.

The perceived noisefloor does seem much lower than any other player I have
heard. This may be a psychoacoustical phenomenon as much as S/N (signal to noise
ratio) specification. This applies whether or not dithered noise is selected.
The ambient noise in my room and the broadband noise of the modified
Assemblage SET300B Signature single-ended valve power amplifier
should be high enough to mask whatever noise is produced by these sources
(except perhaps the Shanling valve output), but the effect is obvious and
repeatable. I am reminded of the effect of removing the Rotel from its
clangy steel case and installing it in a Torlyte box. The Zero One
attention to vibration isolation and power supply isolation could be responsible
for the inky black inter-transient silences achieved in direct cd mode. This
bodes well for the quality of data to be retrieved for the hd archive.

I
choose my first disc to upload, Jimi HendrixFirst Rays of the New
Rising Sun, as I have 25 years familiarity with the material which
originally appeared over three slabs of vinyl posthumously released in '71 &
'72: Rainbow Bridge; The Cry of Love; War Heroes. I have 6
years familiarity with this cd (and its double 180g vinyl equivalent) that hints
at musical directions Hendrix was headed at the time of his death. I know this
material as well as any so it seems ideal to test an entirely unfamiliar format.

The upload is easy. The playback equally easy. That dismisses any user
anxiety engendered by the long instruction manual. As all blokes know, it's
better to try the thing before scaring yourself with the instructions.

Then select HD and press play. Superficially the next statement
does not make sense:The Ti48 archive sounds better than the data
source (cd) direct."What journalistic deceit is this?" demand
plebs chorus, stage-left"I just report what I hear" sayeth ye
scribe"Oh yes? And how many pieces of silver or freebie chattels did the
alchemist Alvin promise you?" demand plebs chorus rapidly evolving into
angry mob,"What snake-oil enhanced signal-processed magik is this?"
they shout,"We must rush to the stone circles and make sacred offerings
to the druids, for this Ti48 is surely alchemy turning base metals into
gold...""we must burn him as a witch" they cry, seizing lighted
brands from the microwave...

Careful reading of the technical design process provides some clues to the
answer. Zero One always intended that the performance of the data retrieved from
the hard drives should exceed that possible from the raw data stored on the cd.
Such an idea usually implies signal processing of an additive kind that is at
best harmless and at worst merely colouration, but Zero One maintain that these
improvements are the inevitable consequence of improving the quantity &
quality of the data by the simple expedients of reducing losses and improving
delivery.

Losses are minimised by sampling and handling at 24bit word-length; the 16bit
cd data is often truncated in playback to 14bits (indeed some early players only
attempt to retrieve at 14bit), where the wider dynamic window of 24bit
capability ensures that whatever is on the disc can reach the hard drives
intact. Although these are usually referred to as "least significant
bits", this comparative term does not indicate that the lost information is
insignificant, merely theoretically less significant. Indeed, this data
at the minimum resolution of dynamic range, when returned to the analogue
domain, provides the subtlest clues to nuances of performance and ambience that
separate a moving recorded performance from a pot-boiler. Allan Wright,
doyen of analogue valve design, uses the term "downward dynamic range" to
describe these effects, and the Zero One does propel downward dynamic range
deeper than the direct cd play. Selecting any word length option lower than
24bit is pointless and my experiments with a Mobile Fidelity Sound Lab cd showed
that with good source material the difference becomes audible; 24bit is
better.

Playback sampling is now fine tuned by careful selection of sampling-rate
either by integer multiplied over-sampling or by the more complex algorithms of
upsampling. Playback filter slopes may now be fine tuned to match the needs of
the combination of chosen sampling rate & individual disc, where this has
often been dictated by choice of hardware in the past. I consistently prefer no
filter.

These decisions are in the information retrieval domain and only the option
of dithered noise falls into the domain of additive signal processing. The
dither combines with these other more fundamental data retrieval factors to
minimise the artefacts remaining after fine tuning, much like the extra valve
stages added to digital-analogue conversion as long ago as the Cal Tempest and
as recently as the Audio Note and Shanling offerings. Legendary Concordant
designer Doug Dunlop used to refer to "pheeoow" as the audible sheen
applied by a good high-end pre-amp to the signals it handled and the dither
control seems to have a similar effect.

The TPDF option has the most
dramatic effect, and is particularly useful at creating an illusion of more
resolution & clarity at high frequencies on softer sounding recordings,
presumably via a sawtooth modulation pattern. Certain classical vocal
recordings, like Arvo Part's O Adonai, have a seductive warmth &
humanity on the 176kHz setting that is compromised by too much softening of high
frequencies on this sampling rate. The TPDF setting works really well at
resharpening this sampling rate choice.

The Nshape effect is very subtle. So subtle it is inaudible on many
recordings, but it does seem to restore ambient cues on live recordings. It
comprises high-passed dither introducing ultrasonic noise at the Nyquist limit
of the sampling rate in use, apparently helping to linearise some DACs. The Ar38
clearly does not need this extra help as I could not hear a difference with most
recordings.

The Nyquist setting creates second-order noise shaping which is
supposed to allow more resolution at low frequencies, at the expense of more
noise at higher frequencies. I would have expected this to be the setting to
contribute to ambience recovery, but again the effect is really subtle. Zero One
note that this is a good choice with sampling rates above 88.2kHz, but I found
the cruder TPDF more useful on the soft-focus four-times oversampled 176kHz.

Surprisingly the speakers needed repositioning to fine-tune the best
performance from this pair. They required less toe-in but moving about 25cm
closer together, to become 2.25m apart at 3m listening distance. the only source
component change that has this effect is some pick-up cartridges (the Denon
DL103 being a notable example). Once optimised the fun can begin with the
various playback tuning options. And it is so much fun. Unlike most tweaks this
can be accomplished on-the-fly while listening and without moving from one's
favourite chair.

Spookily, the various effects are most similar to pick-up impedance loading
changes, or even changes of an entire cartridge. Successful changes of sampling
rate and filter slope are reminiscent of lowering the input impedance for a
Decca London from 47kohm to 33kohm, which opens up the sound making it more
flowing and less mechanical. Despite changes in the digital domain being
expected to have more effect at high frequencies, sampling rate changes also
affect the bass like raising the input impedance for the Supex (and hence old
Linn) moving coils from 100ohm to over 500ohm.

Son (12) thinks treble on Zero One even better than vinyl, but vinyl bass
better. There just is not enough information present on a cd to equal the
ultimate resolving power of good lps, despite the theoretical
advantage of cd for noise, s/n ratio & dynamic range, there is something
about the way analogue data stores & retrieves that must be symbiotic with
human hearing for its obviously more inaccurate information to be more
subjectively satisfying. Perhaps it is the ability to apply a choice of
different noise shaping algorithms that enable the Zero One to emulate so
successfully the analogue experience. My own professional expertise is in the
mind-brain-eye domain where I am aware that the emotional impact of visual
experiences cannot be broken down into simple dimensions of content, form &
optical qualities; so the analogue vs digital debate seems pointless to
me and all that matters is what experience satisfies the individual purchaser.
Regardless of the digital-analogue convergence I report here, how many lps can
be described as "good?".

On balance, the Zero One Ti48 and Ar38 combination offers one of the best
domestic digital playback sources it is my pleasure to enjoy. Added to this is
the user involvement of obsessive tweakery that many audiophiles enjoy. It is
also possible to set a playlist and enjoy for many hours longer than any
conventional source, even radio concerts come to an end sooner than we might
want. Any moments of dissatisfaction may be ameliorated by a quick play with the
settings. The Zero One combo does not have any outstanding performance area to
attract devotees of any particular audio creed but is is not weak in any
performance area, unlike so many single-minded audio approaches to nirvana. It
can tend toward the relentless pace of pre-Cirkus Linn Sondeks and shares that
turntable's bass emphasis centred around 100-150Hz, especially on certain
setting combinations . This is a more modest effect on the Zero One combo than
the Linn, and sounds like power supply choice on the DAC output stage. It
enhances listening most of the time.

Like the best pro-sector products the Zero One Ti48/Ar38 combo does
everything well enough; well enough not to be too irritated by operational
foibles and well enough to enjoy all day.

Switching on our computers & Playstation does not affect the performance
suggesting excellent power supply isolation, even when I tried plugging the
playstation into the dedicated audio mains-ring. After many days of enjoyable
playback I come to load a new playlist and the operating interface just freezes.
I change to the other remote control; I load new batteries and still no joy. So
knowing what works with my pc I manually reboot with the rear panel switch and
this message appears.

Checking system...

Checking music...

As I am a reviewer I get to email the designer directly, who had believed
that when the system experiences an error, if powered down & rebooted it
will display this message until it has recovered but this could take up to 1
hour. After several hours this message remains. I repeat the procedure with the
same result. He telephoned me for another walk-thru instructional then arranges
to have the Ti48 collected.

So this review gets interrupted. This is a new product, using new technology
and perhaps early adopters become Beta testers for situations the designers
hadn't expected, which should not deter adventurous buyers if back-up service is
good; if this type of experience put buyers off there would not be a single pc
or Widows o/s in a single home on the planet. Perhaps I just performed "An
Illegal Operation" or perhaps a "Fatal Exception Occurred" (but this is Linux
OS).

After another long telephone call from Alvin, who was upset that any problem
has occurred, I move the Ti48 to repack it and note that there is a distinct
sound of something loose. A loose hard drive indeed, caused by the wrong screws
being used (the hard drives are US manufactured where they still use non-metric
threads, unlike the technically advanced world) and a dry joint on the
remote-control receiver connection. I am told that both problems are now
rectified in production.

The Ti48 was returned by Alvin's father-in-law and supplied with a new
optional I^2S cable to isolate the ground-planes of the Ti48 & Ar38
in a bid to reduce potential noise even further. This is the first available
optional extra at $200 and I have one of only two samples in the world so I'd
better not break it. After reacquainting myself with the Ti48/Ar38 sound I
swapped cables. The new connection breaks ground loops & lowers system noise
even further in the digital domain, so I expected differences only to be obvious
with no dithered noise. I selected "none", also no filter & 88.2kHz to
maximise differences. Even cold & fresh new the cable is better as if more
data is preserved & more information presented to the DAC. Surprisingly
there is less difference between noise shaping options, which seems
counterintuitive. There is still hardly any difference between output filter
shapes, and I prefer "None". My system is quite immune to rf problems and
the power amplifiers in use are zero-global-feedback, higher feedback designs
might be more adversely affected.

The biggest difference is that the Linn-like bass-hump & relentless pace
is tamed. Pace, Rhythm & Timing performance is improved to a new coherence
that renders Arvo Part's Alina hair raising; it's a piece totally
dependent on impeccable piano timing for its tension & power. This is a
cruel test only matched in timing by the Avondale (on permanent loan) and I can
only wish for an analogue lp of this piece for comparison. The clarity &
low-colouration exceeds my hot-rod Rotel benchmark too.

Vibration Control

Further gains are possible by attention to vibration
control, but the solid construction certainly helps. The pace is affected by the
support to the drive similar to the effects on cd players. Despite the
constrained layer damping of the base the ERaudio
SpaceHarmoniser worked well wedged between the hard plastic feet of the
Ti48, but had little effect on the AR38 (illustrated). The Polychrystal
Reference or Jade IsoDuo feet offer two viable alternatives under the drive,
each an order of magnitude better than the Ti48 feet. The DAC is more happy on
anything other than its own feet. 4 Jade IsoDuos or 5 Isonodes both working
well.

Due to the essential ventilation holes I could not try the Bright Star
LittleRocks directly on the top surfaces of either drive or DAC, but I do find a
LittleRock 5 perched on Bright Star Isonodes improves clarity slightly. Good
support is essential as with any source component.

Conclusion

This has been a steep learning curve for this reviewer. Not
only a technology entirely new to me, but also the opportunity to use it to
compare the effects of sampling rate changes, filter rate changes, noise shaping
& dither through the same chips.I am tweak-drunk with the exertion.I
am despairing of the nasty remote-control.I am impressed by the
performance.I am enjoying hours of music interrupted only by the
shutdown.

The performance of both these components is impressive. They work very well
together and raise domestic digital replay potential to a new level at this
mid-market price. It would be possible to get similar quality, and more high-end
gloss, from a cd only player at a similar price, but such a purchase would only
exceed the Zero One Ti48 & Ar38 performance with the best cds. Where the
Zero One products excel is their capacity to make the most of lesser cds.

This combo did not outperform my vinyl front-end, but came surprisingly
close.

That the Zero One, despite its operational quirks, gets closer to providing
analogue style satisfaction is testament to there being nothing inherently
flawed in digital data storage of music (and most analogue lps are recordings of
data that has been converted to digital & back somewhere between microphone
& laquer) but that it is possible to make better use of even 16bit 44.1kHz
data than conventional cd playback. The noise shaping options might provide
clues to the way the Ti48 converges digital data with analogue experience.

Whether the time separated functions between cd data retrieval and data
playback makes some contribution I do not know. I find it hard to believe that
it could be possible for the hard drive reproduction of data from the cd to
sound better than the direct output of the cd, but it does; every time. This
cuts to the heart of the debates that have raged through the domestic audio
community since the late 70s. It is as if two schools of rationalism collide
again as they did in the 18th century.

The audiophile descendents of the British Empiricist (Berkely, Hume, Locke
etc) branch of Rationalism are locked into ideas that what you hear is what you
get regardless of its likelihood, that this is its own form of objectivity
founded in the ideas that good science emerges from observation of phenomena
followed by attempts to explain those phenomena. Faced off against them are the
objectivist descendents of Continental Rationalism (Descartes, et al) who
continue to argue that if it can't be explained then it can't be happening, and
all else is illusion or delusion. Perhaps the audio community needs an Immanuel
Kant of the 21st century to try to reconcile these discourses and explain to me
what I am hearing and why I am hearing it. The Ti48 output options do not sound
as intuition predicts and the hard-drive does a better job of presenting the
data it has retrieved from the cd than the cd itself. Go figure.

Value judgements of the Zero One are impossible because there is nothing in
my experience similar to compare. While in my system the Zero One archive/DAC
provides some of the most enjoyable listening available from a digital source.
It has also all the play value of tweaking from the comfort of my armchair, what
more may a sybarite ask?

Manufacturer's comment

Firstly, our heartfelt thanks to Mark and to Lucio for such a comprehensive review of our first two products. It is obvious from the effort spent on trying out all the digital processing functions that Mark really did spend a lot of time listening to the Ti48/Ar38 system. Apparently he enjoyed it too, which is a bonus when you have to do work as arduous as audio reviewing.

As this is our first review, of two products that literally were the first to come off the production line, we expected some teething problems - and we got them ! Fortunately, they were relatively minor (wrong screws, poor soldering on a connector) and can easily be (and will be) rectified.
Also, Mark was incorrect when he said that as a privileged reviewer, he was able to email me directly to complain - actually all customers can send me an email to complain (or praise). My email address is given below should you have anything pressing to say right now!
So thanks again to Mark and to TNT for a balanced, positive and very long review!
Alvin Heng - E-mail: a.heng (at) zerooneaudio.com